Lithographic process for dual damascene structures

Abstract

To form a dual damascene structure in a photoresist.SOLUTION: Embodiments of the present disclosure include apparatuses and methods for fabricating dual damascene structures. A first portion in the first region of the photoresist is exposed to a first dose of electromagnetic radiation from a radiation source. The first portion has a first depth and a first surface area. A second portion of the photoresist in the first region is exposed to a second dose of electromagnetic radiation from the radiation source. The second portions have a second depth and a second surface area, and each of the first surface areas of the first portions is disposed within one of the second surface areas of the second portions. A third portion in the second region of the photoresist is exposed to a first dose of electromagnetic radiation from a radiation source. The third portion has a first depth and a first surface area.SELECTED DRAWING: Figure 5

Description

[Background technology]

[0001] Technical Field FIELD OF THE INVENTION

[0001] Embodiments described herein relate generally to lithography processes. More particularly, embodiments of the present disclosure relate to lithography processes for forming dual damascene structures.

[0002] 2. Description of Related Art

[0002] Structures are fabricated using a photosensitive material (such as a photoresist) disposed on a substrate. This is done by partially exposing the photosensitive material to radiation having a particular wavelength, causing the exposed portions of the photosensitive material to become soluble in a developer. The developer is then used to remove the portions of the photosensitive material exposed to the radiation, forming the structure. Typically, to fabricate a structure having multiple features (such as overlapping features), it is necessary to expose multiple portions of the photosensitive material to the radiation multiple times, using multiple scans (e.g., one for each overlapping feature). However, each pass / scan adds time to the fabrication process, reducing throughput.

[0003]

[0003] Therefore, there is a need in the art for a desirable technique that solves the above-mentioned problems. Summary of the Invention

[0004] To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of such one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of the various aspects may be employed.

[0005] An embodiment of the present disclosure provides a method including exposing a first portion within a first region of photoresist to a first dose of electromagnetic radiation from a radiation source. The first portion has a first depth and a first surface area. A second portion within the first region of photoresist is exposed to a second dose of electromagnetic radiation from the radiation source. The second portion has a second depth and a second surface area, and each of the first surface areas of the first portion is disposed within one of the second surface areas of the second portion. A third portion within the second region of photoresist is exposed to the first dose of electromagnetic radiation from the radiation source. The third portion has a first depth and a first surface area.

[0006] An embodiment of the present disclosure provides an apparatus including a radiation source configured to direct electromagnetic radiation toward photoresist disposed on a substrate. The apparatus includes one or more non-transitory computer-readable media having executable instructions stored thereon that, when executed by at least one processor, cause the at least one processor to perform a process including exposing a first portion within a first region of the photoresist to a first dose of electromagnetic radiation from a radiation source. The first portion has a first depth and a first surface area. A second portion within the first region of the photoresist is exposed to a second dose of electromagnetic radiation from the radiation source. The second portion has a second depth and a second surface area, each of the first surface areas of the first portion being located within one of the second surface areas of the second portion. A third portion within the second region of the photoresist is exposed to the first dose of electromagnetic radiation from the radiation source. The third portion has a first depth and a first surface area.

[0007] An embodiment of the present disclosure provides a lithography system including an electromagnetic radiation source. The electromagnetic radiation source is configured to receive one or more user inputs specifying a first dose of electromagnetic radiation, a second dose of electromagnetic radiation, a first set of dimensions for the first dose of electromagnetic radiation, and a second set of dimensions for the second dose of electromagnetic radiation. The electromagnetic radiation source is configured to output an iteration of the first dose of electromagnetic radiation having the first set of dimensions and the second dose of electromagnetic radiation having the second set of dimensions. A substrate support is configured to operatively associate with the electromagnetic radiation source. The substrate support is configured to expose a first portion within a first region of photoresist to the first dose of electromagnetic radiation having the first set of dimensions, expose a second portion within the first region of photoresist to the second dose of electromagnetic radiation having the second set of dimensions, and expose a third portion within the second region of photoresist to the first dose of electromagnetic radiation having the first set of dimensions.

[0008]

[0008] In order that the features of the embodiments of the present disclosure described above may be understood in detail, a more particular description of the present disclosure briefly summarized above will be obtained by reference to embodiments, some of which are illustrated in the accompanying drawings. However, since the present disclosure may also admit of other equally effective embodiments, it should be noted that the accompanying drawings illustrate only typical embodiments of the present disclosure and therefore should not be considered as limiting the scope of the present disclosure. [Brief explanation of the drawings]

[0009] [Figure 1]

[0009] FIG. 1 is a perspective view of a lithography system according to certain embodiments of the present disclosure. [Figure 2]

[0010] 1 is a schematic diagram of a radiation guidance system, according to certain embodiments of the present disclosure. [Figure 3A]

[0011] 1A-1C show schematic diagrams of forming a dual damascene structure in a photoresist disposed over a substrate according to certain embodiments of the present disclosure. [Figure 3B]1A-1C show schematic diagrams of forming a dual damascene structure in a photoresist disposed over a substrate according to certain embodiments of the present disclosure. [Figure 3C] 1A-1C show schematic diagrams of forming a dual damascene structure in a photoresist disposed over a substrate according to certain embodiments of the present disclosure. [Figure 3D] 1A-1C show schematic diagrams of forming a dual damascene structure in a photoresist disposed over a substrate according to certain embodiments of the present disclosure. [Figure 3E] 1A-1C show schematic diagrams of forming a dual damascene structure in a photoresist disposed over a substrate according to certain embodiments of the present disclosure. [Figure 4A]

[0012] 1A-1C show schematic diagrams of forming multiple dual damascene structures in a photoresist disposed over a substrate according to certain embodiments of the present disclosure. [Figure 4B] 1A-1C show schematic diagrams of forming multiple dual damascene structures in a photoresist disposed over a substrate according to certain embodiments of the present disclosure. [Figure 4C] 1A-1C show schematic diagrams of forming multiple dual damascene structures in a photoresist disposed over a substrate according to certain embodiments of the present disclosure. [Figure 4D] 1A-1C show schematic diagrams of forming multiple dual damascene structures in a photoresist disposed over a substrate according to certain embodiments of the present disclosure. [Figure 4E] 1A-1C show schematic diagrams of forming multiple dual damascene structures in a photoresist disposed over a substrate according to certain embodiments of the present disclosure. [Figure 5]

[0013] FIG. 1 is a process flow diagram illustrating a method for exposing portions of a photoresist to electromagnetic radiation from a radiation source, according to certain embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010]

[0014] For ease of understanding, where possible, the same reference numerals have been used to designate identical elements that are common to multiple figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.

[0011]

[0015] FIELD OF THE DISCLOSURE

[0002] Embodiments of the present disclosure relate generally to lithography processes. More particularly, embodiments of the present disclosure relate to lithography processes for forming multi-layer structures (such as dual damascene structures). In one or more embodiments, a lithography system exposes a first portion within a first region of a photosensitive material (referred to herein for brevity as photoresist material) disposed over a substrate to a first dose of electromagnetic radiation from a radiation source. A second portion within the first region of the photoresist is exposed to a second dose of electromagnetic radiation from the radiation source. In some examples, both the first and second portions within the first region may be exposed to electromagnetic radiation without changing (e.g., without realignment) their alignment with the radiation source.

[0012]

[0016] In some embodiments, the electromagnetic radiation emitted from the radiation source is changed from a first dose to a second dose to form the desired pattern in the photoresist layer, and the power of the radiation source is reduced between the first dose and the second dose. In other embodiments, the total exposure time of the second portion is reduced relative to the total exposure time of the first portion to change the electromagnetic radiation emitted from the radiation source from the first dose to the second dose. In one or more embodiments, removing the first portion of the photoresist is configured to form, for example, vias, and removing the second portion of the photoresist is configured to form trenches. The vias and trenches collectively form a plurality of dual damascene structures.

[0013]

[0017] In various embodiments, the first portion and the second portion form an exposed portion in a first region of the photoresist. Alternately / repeatedly, additional first portions in the second region of the photoresist are exposed to a first dose of electromagnetic radiation from a radiation source, and additional second portions in the second region of the photoresist are exposed to a second dose of electromagnetic radiation from the radiation source to form additional exposed portions. The exposed and additional exposed portions are developed using a developer solution to form, for example, multiple dual damascene structures in the photoresist. By exposing the first portion to a first dose of electromagnetic radiation and the second portion to a second dose of electromagnetic radiation in the first region, multiple dual damascene structures are formed with smooth surfaces and in a single scan / pass. This single scan / pass eliminates the risk of positional drift between scans / passes. This is an improvement over conventional techniques that require multiple scans / passes to form dual damascene structures. Additionally, the techniques described herein are an improvement over conventional techniques that use a single exposure to electromagnetic radiation to form structures, which results in structure surfaces that are "rippled" rather than smooth.

[0014] Lithography Process Examples

[0018] 1 is a perspective view of a lithography system 100. The lithography system 100 includes a stage 114 and a processing device 104. In some embodiments, a substrate 120 is supported by the stage 114, which is supported by a pair of tracks 116 disposed above the slab 102. The stage 114 is configured to move along the pair of tracks 116. In one or more embodiments, the pair of tracks 116 includes a pair of parallel magnetic channels.

[0015]

[0019] In various embodiments, an encoder 118 is coupled to the stage 114 and configured to communicate the position of the stage 114 to the controller 122. In some embodiments, the controller 122 includes a computing device having one or more processors, memory, and storage. The one or more processors may include a central processing unit, a graphics processing unit, an accelerator, etc. The memory includes a main memory for storing instructions for the one or more processors to execute or data for the one or more processors to operate on. For example, the memory includes random access memory (RAM). The storage includes mass storage for data or instructions. The storage may include, by way of example and not limitation, a removable disk drive, flash memory, an optical disk, a magneto-optical disk, a magnetic tape, a universal serial bus drive, or two or more of these. The storage may include removable or non-removable media and may be internal or external to the computing device. The storage may include any suitable form of non-volatile memory, solid-state memory, or read-only memory. Controller 122 includes one or more non-transitory computer-readable media. The one or more non-transitory computer-readable media may include one or more semiconductor-based or other integrated circuits (ICs) (e.g., field programmable gate arrays or application-specific ICs), hard disk drives, hybrid hard drives, optical disks, optical disk drives, magneto-optical disks, magneto-optical drives, solid-state drives, RAM drives, any other suitable one or more non-transitory computer-readable storage media, or any suitable combination. The one or more non-transitory computer-readable media may be volatile, non-volatile, or a combination of volatile and non-volatile.

[0016]

[0020] In some examples, the encoder 118 communicates to the controller 122 the position of the stage 114 relative to one or more components of the lithography system 100 (e.g., the pair of tracks 116). In some embodiments, the controller 122 is electrically and / or communicatively coupled to the processing device 104, the stage 114, and the encoder 118. In one or more examples, the processing device 104 may communicate information to the controller 122 regarding the processing and / or alignment of the substrate 120. For example, the processing device 104 may communicate information to the controller 122 indicating that processing of the substrate 120 is complete. The one or more processors of the controller 122 execute instructions that cause the one or more processors to determine which tasks are performed on the substrate 120 and to control the processing times of those tasks. The instructions executed by the one or more processors of the controller 122 also cause the one or more processors to control the position of the substrate 120 relative to the processing device 104.

[0017]

[0021] A processing device 104 is shown including a support 108 and a processing unit 106. In some embodiments, the processing device 104 is positioned over a pair of tracks 116 and includes an opening 112 for the pair of tracks 116 and stage 114 to pass underneath the processing unit 106. In various embodiments, the processing unit 106 includes one or more radiation sources enclosed in a housing 110. In some embodiments, the one or more radiation sources are configured to emit optical radiation (e.g., light having a wavelength in the range of 100 nanometers to 1 millimeter), such as visible light, infrared light, ultraviolet light, or light having a wavelength outside the optical radiation spectrum. In other embodiments, the one or more radiation sources are configured to emit other forms of electromagnetic radiation. To perform one or more tasks determined to be performed on the substrate 120 by one or more processors of the controller 122, one or more radiation sources of the processing unit 106 can expose the surface of the substrate 120 (or a material disposed on the surface of the substrate 120) to electromagnetic radiation when the stage 114 and substrate 120 are disposed below the processing unit 106.

[0018]

[0022] FIG. 2 is a schematic diagram of a radiation guidance system 200. In some examples, the radiation guidance system 200 is included in the processing unit 106. The illustrated radiation guidance system 200 includes a radiation source 202 that emits electromagnetic radiation 204. The radiation source 202 may include a laser, one or more light-emitting diodes (LEDs), or another radiation source capable of generating the electromagnetic radiation 204 (e.g., at one or more particular wavelengths). In some embodiments, the electromagnetic radiation 204 passes through an aperture 206 and a lens 208 before reaching a digital micromirror device (DMD) 210. In various embodiments, the controller 122 is electrically and / or communicatively coupled to the DMD 210 via the processing unit 104. In some embodiments, the DMD 210 includes more than approximately 4 million mirrors, each of which may be controllable individually or in groups. For example, one or more processors in the controller 122 execute instructions that cause the one or more processors to activate / actuate the mirrors of the DMD 210. By actuating / actuating the mirrors of DMD 210, electromagnetic radiation 204 can be directed in the X direction within first ranges 204-1, 204-2 and in the Z direction within a second range (not shown).

[0019]

[0023] In some examples, once electromagnetic radiation 204 reaches a mirror of DMD 210, it may be reflected by a first one of the mirrors of DMD 210 in a first direction relative to substrate 120 (e.g., within first ranges 204-1, 204-2 in the X direction and / or within a second range in the Z direction) as a first “shot” of electromagnetic radiation 204 toward substrate 120. In one or more embodiments, once electromagnetic radiation 204 reaches a mirror of DMD 210, it may be further reflected by a second one of the mirrors of DMD 210 in a second direction relative to substrate 120 (e.g., within first ranges 204-1, 204-2 in the X direction and / or within a second range in the Z direction) as a second “shot” of electromagnetic radiation 204 toward substrate 120. In some embodiments, when electromagnetic radiation 204 reaches the mirrors of DMD 210, it may be reflected by multiple different mirrors of DMD 210 in multiple different directions relative to substrate 120 as multiple "shots" of electromagnetic radiation 204 toward substrate 120.

[0020]

[0024] 3A, 3B, 3C, 3D, and 3E show schematic diagrams of forming a dual damascene structure 316 in a photoresist 306 disposed over a substrate 120. FIG. 3A shows a diagram 300 of the photoresist 306 disposed over the substrate 120. The photoresist 306 may be a positive or negative photoresist, but in various examples is generally described as a positive photoresist. In some embodiments, a first metal layer 308 (e.g., a copper alloy) may be disposed over a second metal layer 310 (e.g., a titanium alloy) between the substrate 120 and the photoresist 306. For example, the photoresist 306 may include a top surface 306T and a bottom surface 306B, and the bottom surface 306B may interface with the first metal layer 308.

[0021]

[0025] Generally, forming a structure including multiple features of various dimensions in photoresist 306 (such as dual damascene structure 316) involves conflicting considerations of total processing time and the final quality of the structure. For example, dual damascene structure 316 may be formed in photoresist 306 using a single exposure of electromagnetic radiation 204 emitted from radiation source 202 and a mask to form the various features. In this example, the single exposure of electromagnetic radiation 204 minimizes total processing time, but at the expense of the final quality of the structure, which may have a "wavy" surface that is not smooth.

[0022]

[0026] In one alternative, the dual damascene structure 316 can be formed in the photoresist 306 by exposing the entire photoresist 306 to a first exposure of electromagnetic radiation 204 emitted from the radiation source 202 to form a first feature. In this alternative, after forming the first feature, the radiation source 202 and the photoresist 306 are realigned, and then the entire photoresist 306 is exposed to a second exposure of electromagnetic radiation 204 to form a second feature. If the radiation source 202 and the photoresist 306 are precisely aligned to form the second feature, this alternative improves the final quality of the structure, which will have a smooth surface. However, this improvement in final quality comes at the cost of overall processing time. Additionally, if the second feature is formed without precise alignment of the radiation source 202 and the photoresist 306, this alternative does not necessarily improve the final structure quality compared to the previous example using a single exposure.

[0023]

[0027] FIG. 3B shows a view 301 in which a first portion 312 of the photoresist 306 has been exposed to a first dose of electromagnetic radiation 204 emitted from the radiation source 202. As shown, the first portion 312 includes a first surface area 312A and a first depth 312D. In some embodiments, the first surface area 312A is approximately 20 square micrometers (μm 2 ) ~ approx. 30μm 2 Within the range of (e.g., about 25 μm2 In other embodiments, the first surface area 312A is about 20 μm 2 Area less than, or about 30 μm 2 The area exceeds this.

[0024]

[0028] First depth 312D is proportional to one or more components of first dose, which in various embodiments includes a first total exposure time of electromagnetic radiation 204 from radiation source 202 to first portion 312 of photoresist 306. Generally, as this first total exposure time decreases, first depth 312D also decreases.

[0025]

[0029] In some examples, the first dose includes a first intensity of electromagnetic radiation 204 from the radiation source 202. The first intensity of electromagnetic radiation 204 from the radiation source 202 is a first power transmitted per first unit area (e.g., first surface area 312A). Generally, as this first intensity decreases, the first depth 312D also decreases. In one or more embodiments, the first intensity of electromagnetic radiation 204 is about 100 mJ / cm 2 ~about 400mJ / cm 2 (For example, about 200 mJ / cm 2 )

[0026]

[0030] In various embodiments, first depth 312D extends from top surface 306T of photoresist 306 to bottom surface 306B of photoresist 306. Therefore, increasing the first total exposure time and / or first intensity does not increase first depth 312D. As shown in FIG. 3B, first depth 312D exposes a portion of first metal layer 308. In some embodiments, first depth 312D can be between about 4.0 micrometers (μm) and about 5.0 μm (e.g., about 4.35 μm). In other embodiments, first depth 312D can be less than about 4.0 μm or greater than about 5.0 μm.

[0027]

[0031] 3C shows the photoresist 306 after the second portion 314 has been exposed to a second dose of electromagnetic radiation 204 emitted from the radiation source 202. In some examples, to change the electromagnetic radiation 204 emitted from the radiation source 202 from the first dose to the second dose, the controller 122 reduces the power output of the radiation source 202. For example, one or more processors of the controller 122 execute instructions that cause the one or more processors to reduce a power setting of the radiation source 202, thereby reducing the intensity of the electromagnetic radiation 204 emitted from the radiation source 202.

[0028]

[0032] In various embodiments, to change the electromagnetic radiation 204 emitted by the radiation source 202 from a first dose to a second dose, the controller 122 does not reduce the power of the radiation source 202, but instead changes the power from a full shot for the first dose to a partial shot for the second dose. In certain embodiments, one or more processors of the controller 122 execute instructions that cause the one or more processors to reduce the duty cycle of the radiation source 202 from, for example, 100 percent for the first dose to, for example, 50 percent for the second dose. In some examples, a full shot for the first dose involves 100 shots of electromagnetic radiation 204 output by the radiation source 202 at a particular output energy dose level. In such examples, a partial shot for the second dose involves 50 shots of electromagnetic radiation 204 output by the radiation source 202 at the particular output energy dose level.

[0029]

[0033] The illustrated second portion 314 includes a second surface area 314A and a second depth 314D. In various embodiments, the second depth 314D is less than the first depth 312D, and the second surface area 314A is greater than the first surface area 312A. In some embodiments, the second surface area 314A is about 200 μm 2 ~about 400μm 2 Within the range of (e.g., about 300 μm 2 In another embodiment, the second surface area 314A is about 200 μm 2Area less than or about 400 μm 2 The area exceeds this.

[0030]

[0034] The second depth 314D is proportional to one or more elements of the second dose. The second dose includes a second total exposure time of the electromagnetic radiation 204 from the radiation source 202 to the second portion 314 of the photoresist 306. Generally, increasing the second total exposure time increases the second depth 314D, and decreasing the second total exposure time decreases the second depth 314D. In some examples, to change the electromagnetic radiation 204 emitted from the radiation source 202 from the first dose to the second dose, the controller 122 changes the output duration of the radiation source 202 from the first total exposure time to the second total exposure time. For example, one or more processors of the controller 122 execute instructions that cause the one or more processors to change the output duration of the radiation source 202.

[0031]

[0035] In one or more embodiments, the second dose can include a second intensity of electromagnetic radiation 204 from the radiation source 202. In some examples, the second intensity can be the same as the first intensity. In other examples, the second intensity can be different from the first intensity (e.g., less than the first intensity). Generally, increasing the second intensity increases the second depth 314D, and decreasing the second intensity decreases the second depth 314D. In one or more embodiments, the second intensity of electromagnetic radiation 204 is about 50 mJ / cm 2 ~about 200mJ / cm 2 (For example, about 100 mJ / cm 2 )

[0032]

[0036] In various embodiments, second depth 314D extends from top surface 306T of photoresist 306 to some portion above bottom surface 306B of photoresist 306. In some embodiments, second depth 314D is within a range of about 2.0 μm to about 3.0 μm (e.g., about 2.3 μm). In other embodiments, second depth 314D can be less than about 2.0 μm or greater than about 3.0 μm.

[0033]

[0037] It should be noted that for a positive-tone photoresist, exposing the first and second portions 312, 314 of the photoresist 306 to electromagnetic radiation 204 from the radiation source 202 causes the first and second portions 312, 314 to become soluble in the developer solution. For example, the electromagnetic radiation 204 from the radiation source 202 may initiate chemical reactions (e.g., cleavage of chemical bonds) in the first and second portions 312, 314 of the photoresist 306, thereby causing the first and second portions 312, 314 to become soluble in the developer solution.

[0034]

[0038] 3D shows a view 303 of a dual damascene structure 316 formed in the photoresist 306. A developer solution (not shown) is applied to the view 302 to remove the first and second portions 312, 314 and form the dual damascene structure 316 in the photoresist 306. As shown, the dual damascene structure 316 includes a via 318 formed by removing the first portion 312 and a trench 320 formed by removing the second portion 314.

[0035]

[0039] 3E illustrates a plan view 304 of dual damascene structure 316. As illustrated in plan view 304, via 318 includes critical dimension 318C. In some embodiments, critical dimension 318C can be between about 3 μm and about 7 μm in length (e.g., about 5 μm). In other embodiments, critical dimension 318C can be less than about 3 μm in length or greater than about 7 μm in length. Additionally, trench 320 includes critical dimension 320C. In some embodiments, critical dimension 320C can be between about 7 μm and about 13 μm in length (e.g., about 10 μm). In other embodiments, critical dimension 320C can be less than about 7 μm in length or greater than about 13 μm in length.

[0036]

[0040] 4A, 4B, 4C, 4D, and 4E show schematic diagrams of forming multiple dual damascene structures 316 in photoresist 306 disposed over substrate 120. FIG. 4A shows a diagram 400 in which a first portion 312, 312-1 in a first region 401 of photoresist 306 has been exposed to a first dose of electromagnetic radiation 204 emitted from a radiation source 202. In some embodiments, first region 401 defines a portion of photoresist 306 in which first portion 312, 312-1 may be exposed to electromagnetic radiation 204 emitted by radiation source 202 by actuating / activating mirrors of DMD 210 to direct electromagnetic radiation 204 within first ranges 204-1, 204-2 in the X-direction. Thus, in one or more embodiments, the first portion 312, 312-1 can be exposed to electromagnetic radiation 204 in the first region 401 without changing the alignment of the radiation source 202 with the photoresist 306 or without realigning the radiation source 202 with the photoresist 306.

[0037]

[0041] 4B shows a diagram 402 in which second portions 314, 314-1 in a first region 401 of the photoresist 306 have been exposed to a second dose of electromagnetic radiation 204 emitted from the radiation source 202. In one or more embodiments, the first region 401 defines a portion of the photoresist 306 in which the second portions 314, 314-1 may be exposed to electromagnetic radiation 204 emitted by the radiation source 202 by actuating / triggering mirrors of the DMD 210 to direct the electromagnetic radiation 204 within a first range 204-1, 204-2 in the X direction. Thus, in some embodiments, the second portions 314, 314-1 may be exposed to electromagnetic radiation 204 in the first region 401 without changing the alignment of the radiation source 202 and the photoresist 306 or without realigning the radiation source 202 and the photoresist 306. Note that the first portion 312 and the second portion 314 collectively form the exposed portion 406. For example, the first portion 312-1 and the second portion 314-1 also collectively form the exposed portion 406. In the above-described technique, by utilizing the first region 401 to form the exposed portion 406, both the total processing time and the final structure quality are improved compared to conventional techniques. In a first example, the exposed portion 406 may be formed by forming the first portions 312 and 312-1 and then forming the second portions 314 and 314-1. In a second example, the exposed portion 406 may be formed by forming the second portions 314 and 314-1 and then forming the first portions 312 and 312-1. In a third example, the exposed portion 406 may be formed by forming the first portion 312, forming the second portion 314, forming the first portion 312-1, and then forming the second portion 314-1. Regardless of the procedure by which the exposed portions 406 are formed, multiple exposed portions 406 may be formed in the first region 401 in a single scan / pass without realigning the radiation source 202 with the photoresist 306.

[0038]

[0042] FIG. 4C shows a view 403 of an additional exposed portion 406 formed in the first region 401. FIG. 4D shows a view 404 of a plurality of dual damascene structures 316 formed in the photoresist 306. A developer solution (not shown) is applied to the view 403 to remove the exposed portion 406 from the plurality of dual damascene structures 316 in the photoresist 306. FIG. 4E shows a plan view 405 of the plurality of dual damascene structures 316. The plan view 405 shows the first region 401 as well as additional regions 407-410. In each of the additional regions 407-410, a first portion 312, 312-1 and a second portion 314, 314-1 can be formed by actuating / activating mirrors of the DMD 210 to direct electromagnetic radiation 204 within first ranges 204-1, 204-2 in the X direction. Thus, exposed portions 406 may be formed in each of the additional regions 407-410 to fabricate multiple dual damascene structures 316 without ever realigning the radiation source 202 and the photoresist 306. As shown, one or more processors in the controller 122 execute instructions that cause the one or more processors to form multiple damascene structures 316 with smooth surface features in a single scan / pass to eliminate the possibility of positional drift between scans / passes. This is not possible using conventional techniques that are limited to forming structures with non-smooth, "wavy" surfaces or to realigning the photoresist 306 and the radiation source 202.

[0039]

[0043] 5 is a process flow diagram illustrating a method 500 for exposing portions of photoresist to electromagnetic radiation from a radiation source. In step 502, a first portion in a first region of the photoresist having a first depth and a first surface area is exposed to a first dose of electromagnetic radiation from the radiation source. In some embodiments, a first portion 312, 312-1 in a first region 401 of the photoresist 306 having a first depth 312D and a first surface area 312A is exposed to a first dose of electromagnetic radiation 204 from the radiation source 202.

[0040]

[0044] In step 504, second portions in the first region of the photoresist, having a second depth and a second surface area, are exposed to a second dose of electromagnetic radiation from the radiation source. Each of the first surface areas of the first portions is disposed within one of the second surface areas of the second portions. In one or more embodiments, second portions 314, 314-1 in the first region 401 of the photoresist 306, having a second depth 314D and a second surface area 314A, are exposed to a second dose of electromagnetic radiation 204 from the radiation source 202. In step 506, a third portion in the second region of the photoresist, having the first depth and the first surface area, is exposed to a first dose of electromagnetic radiation from the radiation source. In various embodiments, a first portion 312, 312-1 in the additional region 407 of the photoresist 306 having a first depth 312D and a first surface area 312A is exposed to a first dose of electromagnetic radiation 204 from the radiation source 202.

[0041] Further considerations

[0045] In the above description, details are set forth as examples to facilitate understanding of the disclosed subject matter. However, it will be apparent to those skilled in the art that the disclosed implementations are illustrative and do not encompass all possible implementations. Therefore, it should be understood that reference to the described examples is not intended to limit the scope of the present disclosure. It is fully anticipated that any and all changes and further modifications to the described devices, apparatus, methods, and all further applications of the principles of the present disclosure will normally occur to those skilled in the art to which the present disclosure pertains. In particular, it is fully anticipated that features, components, and / or processes described in connection with one implementation can be combined with features, components, and / or processes described in connection with other implementations of the present disclosure. As used herein, the term "about" may indicate a + / - 10% variation from the nominal value. It should be understood that such variations can be included in any value presented herein.

[0042]

[0046] As used herein, "a processor," "at least one processor," or "one or more processors" generally refers to a single processor configured to perform one or more operations, or to multiple processors configured to collectively perform one or more operations. When multiple processors are used, performance of one or more operations may be divided among separate processors, but it is also possible for one processor to perform multiple operations, and for multiple processors to collectively perform a single operation. Similarly, "a memory," "at least one memory," or "one or more memories" generally refers to a single memory configured to store data and / or instructions, or to multiple memories configured to collectively store data and / or instructions.

[0043]

[0047] As used herein, a reference to "at least one of" listed items refers to any combination of such items (including a single item). As an example, "at least one of a, b, or c" is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination with multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or a, b, and c in any other order).

[0044]

[0048] The methods disclosed herein include one or more steps or actions for achieving the described method. The steps and / or actions of the methods may be interchanged with one another without departing from the scope of the claims. In other words, unless a particular order of steps or actions is specified, the order and / or use of the particular steps or actions may be changed without departing from the scope of the claims.

[0045]

[0049] While the above description is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, the scope of which is determined by the following claims. [Explanation of symbols]

[0046] TIFF2026009830000002.tif248170TIFF2026009830000003.tif252170TIFF2026009830000004.tif70170

Claims

1. 1. A method comprising: exposing a first portion in a first region of the photoresist, the first portion having a first depth and a first surface area, to a first dose of electromagnetic radiation from a radiation source; exposing second portions in the first region of the photoresist, the second portions having second depths and second surface areas, to a second dose of electromagnetic radiation from the radiation source, wherein each of the first surface areas of the first portions is disposed within one of the second surface areas of the second portions; exposing a third portion in the second region of the photoresist, the third portion having the first depth and the first surface area, to the first dose of electromagnetic radiation from the radiation source; A method comprising:

2. exposing fourth portions in the second region of the photoresist, the fourth portions having the second depth and the second surface areas, to the second dose of electromagnetic radiation from the radiation source, wherein each of the first surface areas of the third portions is disposed within one of the second surface areas of the fourth portions; The method of claim 1 further comprising:

3. 3. The method of claim 2, wherein the fourth portion is exposed in a scan that includes exposing the first portion to the first dose of electromagnetic radiation from the radiation source.

4. The method of claim 1 , wherein the first depth is greater than the second depth.

5. 5. The method of claim 4, wherein the first depth extends from a top surface of the photoresist to a bottom surface of the photoresist.

6. 10. The method of claim 1, wherein the first dose of electromagnetic radiation from the radiation source has a first intensity and the second dose of electromagnetic radiation from the radiation source has a second intensity, the first intensity being greater than the second intensity.

7. 10. The method of claim 1, wherein the electromagnetic radiation from the radiation source has an intensity at the first dose and the electromagnetic radiation from the radiation source has the intensity at the second dose.

8. The method of claim 7 , wherein the total exposure time at the first dose is longer than the total exposure time at the second dose.

9. 10. The method of claim 1, wherein removing the first and second portions from the photoresist is configured to form a plurality of dual damascene structures.

10. 10. The method of claim 9, wherein removing the second portion is configured to form a trench and removing the first portion is configured to form a via.

11. developing the photoresist after exposing the third portion; forming a plurality of dual damascene structures in the photoresist; The method of claim 1 further comprising:

12. 1. An apparatus comprising: a radiation source configured to direct electromagnetic radiation toward a photoresist disposed on the substrate; one or more non-transitory computer-readable media storing executable instructions; the executable instructions, when executed by at least one processor, cause the at least one processor to: exposing a first portion in a first region of the photoresist, the first portion having a first depth and a first surface area, to a first dose of electromagnetic radiation from the radiation source; exposing second portions in the first region of the photoresist, the second portions having second depths and second surface areas, to a second dose of electromagnetic radiation from the radiation source, wherein each of the first surface areas of the first portions is disposed within one of the second surface areas of the second portions; exposing a third portion in the second region of the photoresist, the third portion having the first depth and the first surface area, to the first dose of electromagnetic radiation from the radiation source. Device.

13. 13. The apparatus of claim 12, wherein an intensity of the first dose of electromagnetic radiation from the radiation source is reduced to expose the second portion to the second dose of electromagnetic radiation from the radiation source.

14. 13. The apparatus of claim 12, wherein the first dose comprises a first total exposure time and the second dose comprises a second total exposure time that is shorter than the first total exposure time.

15. The apparatus of claim 12 , wherein the first depth is greater than the second depth.

16. 16. The apparatus of claim 15, wherein the first depth extends from a top surface of the photoresist to a bottom surface of the photoresist.

17. 13. The apparatus of claim 12, wherein removing the first portion and removing the second portion from the photoresist is configured to form a plurality of dual damascene structures.

18. The apparatus of claim 17 , wherein removing the first portion is configured to form a via.

19. The apparatus of claim 17 , wherein removing the second portion is configured to form a trench.

20. 1. A lithography system comprising: receiving one or more user inputs specifying a first dose of electromagnetic radiation, a second dose of electromagnetic radiation, a first set of dimensions for the first dose of electromagnetic radiation, and a second set of dimensions for the second dose of electromagnetic radiation; outputting an iteration of the first dose of electromagnetic radiation having the first set of dimensions and the second dose of electromagnetic radiation having the second set of dimensions; an electromagnetic radiation source configured to: operatively associated with said electromagnetic radiation source; exposing a first portion in a first region of the photoresist to the first dose of electromagnetic radiation having the first set of dimensions; exposing a second portion of the photoresist in the first region to the second dose of electromagnetic radiation having the second set of dimensions; exposing a third portion in the second region of the photoresist to the first dose of electromagnetic radiation having the first set of dimensions; a substrate support configured to perform A system comprising:

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